My truck continues to throw trouble code PO159. This code indicates the engine air fuel ratio is not being adjusted by the oxygen sensor signal or the ECM as expected to do so, or not adjusted as often as expected to do so once the engine is warmed or under normal engine use.

I have replaced the #2 O2 sensor and initially the trouble code went away. Shortly thereafter(maybe 10-15 miles) the CEL came back on and after running code reader, it is the same code.
CEL will turn off on its own when ambient temperature gets above 50-60 degrees making this even more of a head scratcher.
Not sure if this is related, but when filling truck with gas the gas will almost overflow out of the fill spout and 'gurgle' and then finally recede in to the tank.

Any thoughts on what could be causing this code to keep coming back, and coming back only when the air temp is below 50?
I am at my wits end and really want to get this resolved. I have taken it to the Dodge dealership and they run the code reader and turn the code off but never fix the problem because the light continues to come back on.

 

What brand sensor? Bosch is known to cause issues like this. I'd change the upstream one also if you run out of options. Maybe it could throw the other off?

 

I had the same error code. I replaced all 4 sensors in my 08 and the code would keep coming back.

About a month ago my Catalytic Converter developed a leak in the top of the flange and I was able to weld it back together and I no longer get the code popping up.

It's worth checking into.

 

Thanks for that reply. I will check around the catalytic converter for leaks. I know that the heat shield on the catalytic converter is busted loose on the side I can see so who knows what the other side might look like!
Thanks again.

 

I bought a brand new Mopar 02 sensor